System and method for monitorinig mold flux consumption

ABSTRACT

A system for monitoring the consumption of mold flux in a continuous casting apparatus including a transfer apparatus for transferring mold flux from a bulk source to an intermediate hopper; a feed control apparatus for controlling the transfer of mold flux from the transfer apparatus to the intermediate hopper, the feed control apparatus including at least one load cell for weighing the intermediate hopper and the mold flux within the intermediate hopper over a period of time, the feed control apparatus further including a controller receiving input from the at least one load cell and for controlling the operation of the transfer apparatus based on the input; and a delivery apparatus for receiving mold flux from the intermediate hopper and delivering the mold flux to a mold, the delivery apparatus pneumatically feeding the mold flux to the mold.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit under 35 U.S.C. §119(e) of theearlier filing date of U.S. Provisional Patent Application No.61/540,616 filed on Sep. 29, 2011, which is hereby incorporated byreference.

FIELD OF THE INVENTION

This application discloses an invention which is related, generally andin various embodiments, to the metal casting field wherein mold fluxconsumption is monitored.

BACKGROUND OF THE INVENTION

It is customary to apply a mold flux, which may be a powder or granularmaterial, onto the top of a shapes mold during the continuous casting ofa molten metal, typically steel, as shown in U.S. Pat. No. 6,474,398,the disclosure of which is incorporated by reference. The mold fluxturns into slag when sufficiently heated by the molten steel. Typically,the mold flux being fed is in the form of a granulated powder from abulk source such as a bag. The mold flux is fed by way of a vacuum fromthe bulk source to an intermediate feeder hopper. In prior arrangementssuch as that shown in U.S. Pat. No. 6,474,398, a constant level ismaintained within the intermediate hopper with a proximity sensor whichmeasures the level of mold flux within the hopper. The operator adjuststhe set point level on a feed controller to deliver a steady feed ofMold flux from a feed box.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the invention are described herein in by way ofexample in conjunction with the following figures, wherein likereference characters designate the same or similar elements.

FIG. 1 illustrates a front view of various embodiments of a system formeasuring mold flux consumption in a continuous casting operation.

FIG. 2 illustrates a back perspective view of the system of FIG. 1.

DETAILED DESCRIPTION

It is to be understood that at least some of the figures anddescriptions of the invention have been simplified to illustrateelements that are relevant for a clear understanding of the invention,while eliminating, for purposes of clarity, other elements that those ofordinary skill in the art will appreciate may also comprise a portion ofthe invention. However, because such elements are well known in the art,and because they do not facilitate a better understanding of theinvention, a description of such elements is not provided herein.

FIG. 1 illustrates various embodiments of a system 10 for measuring moldflux consumption in a continuous casting operation; common parts will berepresented by the same reference numeral. As shown, the continuouscasting operation is for the continuous casting of any shape, frommolten metal 15, which in the illustrated embodiment is molten steel.Mold flux 11 in granular or powder form is fed onto the top of theshapes mold 13. The shapes mold can be, by way of example, a slab mold.The mold flux 11 becomes a slag when sufficiently heated by the moltensteel.

The system of various embodiments is indicated generally by referencenumber 10. The system generally includes four major components: atransfer apparatus 12; an intermediate hopper 14, a feed controlapparatus 16, and a delivery apparatus 18. The transfer apparatus 12transfers powder mold flux from a bulk source 20 to the intermediatehopper 14. The bulk source of powder mold flux 20 may be, for example, alarge bag or barrel. After the delivery apparatus 18 feeds powder moldflux 11 from the intermediate hopper to the top of the mold.

The transfer apparatus includes a vacuum 22 having an inlet port 24 towhich one end 26 of a flexible suction tube 28 is connected. The otherend 30 of flexible suction tube 28 extends into the bulk source 20.Vacuum 22 has an outlet at the bottom for transferring mold flux to theintermediate hopper 14. On the bottom of the vacuum hopper 22, there isa valve such as a flapper 43 with a counter weight attached. While thevacuum 22 is energized this creates a seal between the flapper 43 andthe bottom of the vacuum bin 22. When the vacuum 22 stops, the weight ofthe material that was picked up allows the flapper 43 to open and thematerial drops into the intermediate hopper 14. The intermediate hopper14 has a fitting on the bottom that extends into the top of the feedhopper 31. The delivery apparatus 18 includes a feed hopper 31 and feedsmold flux from a pair (could be up to six outlets) of outlet ports 32,34 of the feed hopper 31 to the top of a mold. There is no contactbetween the intermediate hopper 14 and feed hopper 31 as this would givea false weight.

The delivery apparatus 18 includes a pair (could be up to six deliverytubes) of delivery tubes 36, 40 each having one end connectable to anoutlet port 32, 34, and the other end having anywhere from one to sixfeed heads 46 (two shown in the illustrated embodiment) disposed above amold or series of molds. The mold flux is pneumatically fed from thefeed hopper 31 with 1 inch venturi pumps 41 which are operativelyconnected to the outlet ports 32, 34. The number of ports or 1 inchventuri pumps could vary depending on the type of continuous castingmachine or shapes cast. For example: If the continuous caster is a small6-strand billet machine, there would be a total of six molds, each moldbeing the size of the cast product. This would require six 1 inchventuri pumps and feed lines.

The control apparatus 16 includes at least one load cell 42 supportingthe intermediate hopper 14 for weighing the intermediate hopper 14 andits contents of mold flux over a period of time for measuring the realtime consumption of mold flux. The at least one load cell 42 preferablyincludes a plurality of load cells 42, each supporting a side of theintermediate hopper 14. There are three load cells 42 in thisembodiment. Only two load cells 42, however, can be seen in FIG. 1. Thecontrol apparatus further includes a programmable logic controller (PLC)44 (FIG. 2) receiving input from the load cells for controlling theoperation of the vacuum 22. The PLC 44 causes the vacuum 22 to turn on,thus causing mold flux to feed into the intermediate hopper 14, based ona predetermined weight of the feed bin as compared to the consumption orloss of weight of mold flux calculated using the output of the at leastone load cell 42. The use of PLC 44 allows the ability to record dailymold flux consumption files. Alternative to a PLC 44, any suitableprocessor having the appropriate software such as FACTORY TALK softwaremay be used. Also, alternative to measuring mold flux consumption byweight, it may be desirable to measure mold flux consumptionvolumetrically. The rate of which the mold flux is delivered onto themold can be adjusted by the operator using an operator control screen 48on the PLC 44 that can be used for adjusting the feed rate. The operatorcontrol screen 48 is a touch screen display that gives the operator ascale of 0-100. This scale represents the mA voltage sent from the PLC44 to the current to pressure transducers that are located in the feedhopper. Alternatively, the rate of which the mold flux is delivered ontothe mold can be adjusted by the operator by a handheld wirelesscontroller 50 in communication with a receiver 52 on PLC 44. Thewireless controller 50 can be used to control the feed rate instead ofthe operator control screen 48 on the PLC display.

Nothing in the above description is meant to limit the invention to anyspecific materials, geometry, or orientation of elements. Manypart/orientation substitutions are contemplated within the scope of theinvention and will be apparent to those skilled in the art. Theembodiments described herein were presented by way of example only andshould not be used to limit the scope of the invention.

Although the invention has been described in terms of particularembodiments in this application, one of ordinary skill in the art, inlight of the teachings herein, can generate additional embodiments andmodifications without departing from the spirit of, or exceeding thescope of, the claimed invention. Accordingly, it is understood that thedrawings and the descriptions herein are proffered only to facilitatecomprehension of the invention and should not be construed to limit thescope thereof.

1-11. (canceled)
 12. A method for monitoring mold flux consumption anddelivering mold flux onto a continuous casting mold, the methodcomprising: transferring mold flux from a bulk source to an intermediatehopper using a transfer apparatus; weighing the intermediate hopper andthe mold flux within the intermediate hopper over a period of time tomeasure mold flux consumption in real time; making a record of mold fluxconsumption over time; controlling the operation of the transferapparatus based on the weight of the intermediate hopper and the moldflux within the intermediate hopper; transferring mold flux from theintermediate hopper to a feed hopper; and pneumatically feeding the moldflux from the feed hopper to a continuous casting mold.
 13. The methodof claim 12, wherein the mold flux consumption is measured by weight.14. The method of claim 13, wherein the weighing of the intermediatehopper and the mold flux within the intermediate hopper is accomplishedusing at least one load cell, and wherein the mold flux consumption iscalculated based on an output of the at least one load cell.
 15. Themethod of claim 12, wherein the intermediate hopper does not contact thefeed hopper.
 16. The method of claim 12, wherein the mold fluxconsumption is measured volumetrically.
 17. The method of claim 12,wherein the making a record of mold flux consumption over time includesusing a PLC to record daily mold flux consumption.
 18. The method ofclaim 12, wherein the pneumatic feeding of the mold flux from the feedhopper to the mold occurs at a rate that is manually controlled by anoperator.
 19. The method of claim 18, wherein operator controls thepneumatic feeding using a touch screen display.
 20. The method of claim18, wherein operator controls the pneumatic feeding using a handheldwireless controller.